Liquid-control means for hydraulic brakes



April 9, E929.v L. L. REcKLl-:R 3,708,153

LIQUID CONTROL MEANS FOR HYDRAULIC BRAKES Filed Oct. 20. 1926 mi.. f

INVENTOR. 690]@ 6F Parenteel am. e, ieee.

naman sTiTas TaTaaT carica.

LAURENCE Il. REGKLER, OF WESTWOOD, CALIFORNIA.

LIQUID-CONTROL MEANS FOR HYDRAULIC BRAKES.

Application led October 20, 1926. Serial No.`142,817.

This invention relates to improvements in liquid control means for fourwheel hy" to cause the liquid to be normally equalized v to all fourbrakes and to enable the braking pressure to be applied to any three outof the four brakes inthe event that a leak de veloped in the liquid lineof the other brake. This construction represented a considerableimprovement over braking systems now in use in which a leak in the lineto one brake causes all the other brakes to be rendered inoperative.This very feature, however, also proved a source of danger, since if a'leak should happen to develop in the line to one of the front brakes,the other front brake' couldstill be applied and this would cause animmediate slewing around of the wheels if an intensely tight grip wasnot maintained on the steering wheel, and even thiswould,

probably not entirely eliminate the swerving of the car.

The principal object of the present invention therefore is to eliminatethe above de-y fective feature by arranging the control apparatus sothat if one front brake should be rendered inoperative by a leak in theoil line, the other front brake would likewise and automatically berendered inoperative. At the same time the rear brakes remain operativeso that the braking power even then would be`equal to that obtained onordinary two-brake cars. The liquid equalizing feature is retained andnormally functions to equalize the liquid to all the four brakes, and isnot affected by the first men' tioned feature of the apparatus.

A further object of the invention is to produce a simple and inexpensivedevice andyet one which will be exceedingly effective for the purposefor which it is designed.

These objects lI accomplish by mea-ns of such structure and relativearrangement of part-s as will fully appear bya perusal of the followingspecification and claims.

In the drawings similar characters of reference indicatecorresponding'parts in the several views:

Fig. 1 is aplan outline of a motor ve- `control means applied thereto.

hicleshowing a four-wheelA brake structure thereon with m'y improvedform of fluid Fig. 2 is a fragmentary side elevation showing a pedalcontrol` mechanism'for the operating plungers.

'Fig'. 3 1s a sectional elevation of the pre ferred form of cylinder andplunger unit cletached.

i Fig. lis-a cross section on the line 4 4 of I Fig.

'Fig'.f is .across section of a modified form ofcyilnder unit.

Fig 6 is a vertical section on the line (36 of Fig. 5.

.Referring now more particularly lto the characters'ofreference on'thedrawings, and particularly at present to Figs. 1 to 4, 1 denotes thefront wheel brake units of a motor vehicle,-and 2 the rear wheel brakeunits thereof.- 'Ihe particular form of brake mechanism forms no part ofmy invention, but in any' case leach'such unit has a pipe' for theliquid, usually oil, leading vthere.v

from. In the drawings denotes the pipes 'from the front brakes and 4 the'pipes from the rear brakes. The pipes 3 converge .to a fitting 5 whichis mounted in and com-v municates with the bottom of a vertical cylinder6. lThe pipes 4 lead individually to a separate pair of otherverticalcylinders 7 which are formed in Aunitary association with thecylinder 6 in a block 8. The cylinders and pipes of the system areintended to be vmaintained entirely full of oil, as is customary.

Rods 9 are slidable through the top cap 10 of the cylinder block withplungers 11 of leather or the like :on their inner ends impinging snuglyagainst the walls of the cylinders. The .rods outwardly of the cap arerigidly connected to a single head 12 having a stem 13 projectingupwardly therefrom. vThis stem is adapted to be engaged by the lower endof a' lever 14 of suitable form, having a footpad 15 on its upper end.This lever as usual with hydraulic brakes, takes the place of theordinary service brake foot lever.

Intermediate the upper and lower limits of movement ofthe plungers,small passages 16 provide communication between the different cylinders.In operation therefore the oil level in the different cylinders willnormally always be the same, insuring a fully equalized operation ofthebrakes,fas

,pipes 4 o'r inthe mechanism associated thereWith-theoil w-ill of coursebe drained lfrom'the corresponding cylinder.

The oil will also be drained to a Certain extent from the othercylinders, but only-to the level 0 f` l Vthe passages 16.l'lhisvvillthen stilll per-.f

I claim. as new and useful and desire to se- ,cure by Letters Patent is:

mit one of. the rear brakes and the two iron'ty brakes being a plied.511i, however,

a leak should develop 1n either ofthe pipes 3 the corresponding cylinder6 will been-V tirely drained, and even though the other4 pipe 3 itselfshould remain full of oil, the downward movement 0f the plungers. Y1n

' lvsaid cylinder` Will of course impart no pressure to such oil. 'Boththe front wheel brakes will thcreforebe rendered inoperative andthedangerous -svverving of the vehicle g frontl bra'keapplication isReferring now to Figs. 5 and 6, the same results may be obtained byusing a airof cylinders 6a for thelfront brakes Wit indi.- vidualplungers' 11a therein, in addition to the cylinders 7 a for the rearbrakes. In this case the pipes 3 to the front brakes are connectedindividually to the cylinders 6a.

To cause the draining 'bf both cylinders 6a to take place. if a leak toone of the front brakes should develop,l said cylinders 6a haveanimer-communicating passage 17 at 'the bottom', independent of theupper equal- 4izing passages 16. this means the same results areobtained as was the c'ase lWith the ,lirst described type, as will beevident.

From; the foregoingdescription itwill be readily lseen that Ihaveproduced such claims.

a device as substantially fulfills the objects of the inventionas setforthherein.

While this speciication sets forth in d'e- I tail the'pl'esent andpreferred construction ofthe device, still 4in practice such deviationsfrom such detail may beresorted to as do not form a departure from thespirit of the invention, as defined by the appended Having thusdescribed my invention what 1. A .liquid 'control structure Afor fourlWheel hydraulic brakes comprising With. pipes leading fromA theAindividual brakes, a

member having `cylinders t6 the bottoms of which the pipes areindividually connected,

plungers in 'the cylinders, means for de'- p'ressing the plungerssimultaneously, and means whereby if the 'liquid drains out from onefront-Wheel brake pipe no pressure Will.y

beimpafrte'd to the liquid in the other front- Wheel brake pipe upondepressing: the

`plungers Without interfering with the im- .partingof pressure to thebrake Y pipes .of the other cylinders and brakes. 4i

2.` A liquid control structure for four- Wheel hydraulic brakesjcomprising with pipes leading vfrom the individual brakes,

a 'member having cylinders to the bottoms of which the pipes areindividually connected, plungers in the cylinders, and means fordepressing the plungers simultaneously;

' LAURENCE L. RECKLER.

